JP2009512132A - UV active electronic window - Google Patents

Abstract

A surface light source (1) having a first light source (2) emitting light (L2) in a first wavelength band and a light transparent carrier screen (4) coated with a phosphor layer (5) Disclosed. The surface light source further comprises at least one additional light source for projecting light L3 in a second wavelength band different from the first wavelength band onto the carrier screen (4). The light L3 can excite the phosphor layer (5).

Description

  The present invention includes a first light source that emits light in a first wavelength band, and a light-transparent carrier screened with a phosphor layer coated with a phosphor layer. Related to the light source.

  Light projection is known from many applications. Also, the use of UV light combined with phosphorus for conversion to visible light is well known and widely used in fluorescent lamps. This also exists in the form of wide area planar light sources known in the art. In JP-A-08 045 321 (Patent Document 1), a plurality of gas discharge lamps radiating in the same ultraviolet wavelength band are arranged to illuminate on a light-transmitting sheet coated with a fluorescent agent, and the fluorescence The agent is continuously excited by UV radiation and emits visible light through the sheet as it fluoresces.

  Here, measures are taken to obtain uniformity in visibility, resulting in uniform illumination. The use of a wide screen range emitted by multiple light sources eliminates the shadowing effect and avoids visible non-uniformities. In order to avoid shielding effects, the phosphor coating must be applied evenly across the entire screen.

  However, this structure does not allow local illumination of the screen. The illumination system has a plurality of invisible light sources. The structure is limited to light sources that generate only radiation other than at visible wavelengths. Furthermore, pixelation of the generated visible light cannot be performed. Also, a multicolor lamp cannot be constructed in this way. This solution limits the performance of the lighting system.

This mechanical structure is limited to a rectangular parallel piped box with a phosphor coating layer formed on the inner side and limits the freedom in the manufacture and use of such lamps.
JP-A-08 045 321

  The present invention seeks to overcome existing problems associated with wide area planar light sources. The present invention further increases flexibility by providing a surface light source having a first light source that emits light in a first wavelength band and a light transparent carrier screen coated with a phosphorous layer. Furthermore, the present invention comprises at least one additional light source that projects light in a second wavelength band different from the first wavelength band onto the carrier screen. The projected light can excite the phosphorous layer. Phosphorous preferably emits light in the visible wavelength band.

  Phosphorous coatings can be placed on each side of the carrier screen depending on the conditions of the particular case, as long as they can be excited by additional light sources, to provide appropriate advantages.

  The use of an additional light source that can excite the phosphorous layer in combination with the first light source provides additional degrees of freedom in terms of color, intensity variations, and spatial variations.

  According to one aspect of the invention, the carrier screen and the phosphor coating are placed between the object to be illuminated and the additional light source. This is advantageous because the carrier screen can be used as a filter or filter carrier. The screen, for example, has the property of filtering UV components from additional light sources, thus preventing inappropriate radiation from reaching an object such as an observer. The carrier screen can also be arranged to allow the passage of such UV light quantities, effectively acting as a suitable substitute for sunlight in tanning devices or other situations.

  As an opposite alternative, an additional light source is placed between the carrier screen and the object to be illuminated. This is advantageous when the carrier screen forms part of a first light source, which can be, for example, an illumination box, in which case it is convenient to apply a coating on one side of the diffuser of the lighting box. It is a solution.

  An additional carrier or filter element is then arranged between the observer and the additional light source, for example to protect the observer from harmful radiation according to the above.

  The additional light source may have multiple light sources that can be controlled independently. This further increases the potential for dynamics and variations in the device of the present invention. The spatial distribution of the light sources can give a dynamic spatial distribution effect.

  According to one aspect of the present invention, at least one of the plurality of independently controllable objects irradiates light having a wavelength spectrum different from the others, thereby further enhancing the dynamics. This provides a variety of effects that are possible when combined with the feature that the phosphorus coating has multiple layers and / or structures with the same or different phosphorus materials. This also allows for selectively activating various portions of the phosphor material on the carrier screen to display various patterns in structure and space. That is, spatial variations can be obtained by appropriate patterning of the phosphor layer, or by local excitation / activity of the phosphor layer or a combination thereof. Ultimately, a variety of UV light sources can be used with different wavelengths or outputs, enhancing the effect of geometric and spatial variations of visible output light.

  Additional light sources are also in methods used for IC patterning, such as scanning UV spots or controllable UV light sources, eg based on DMD technology or such as “UV pointers”. Based on, it may have an image projection device. The apparatus constitutes a UV optically addressed display. The additional light source may also have a scanning UV laser. For simplicity, this type of device is referred to herein as a UV beamer.

  In the apparatus of the present invention, a suitable material for the carrier screen can be glass if UV light is to be suppressed, and can be quartz glass otherwise. The material may also include a bendable or flexible plastic sheet, a woven structure, or other material that may be suitable for a particular situation.

  Additional light sources may include LEDs, gas discharge devices, and the like.

  Combinations of electrical addressable phosphor layers (such as Electro Luminescence from Durell) and UV activity are also possible. Known structures have a layer stack applied over a substrate, such as a glass substrate or a flexible foil substrate. In one embodiment, the phosphor layer and the dielectric layer are sandwiched between conductive layers. The pressure applied to the conductive layer advances an electric field in the phosphorous layer that accelerates electrons (A voltage applied to the conductive layers and electrical field with the phosphor layer.). Such electrons activate the phosphor particles and emit visible light. As the capacitance formed by the dielectric layer is changed by electrons, the electric field across the phosphor layer is reduced and light emission stops while the electric field across the dielectric layer increases. In the case of an AC drive, the external voltage is reversed, accelerating the stored electrons back to the phosphorus layer while activating the phosphorus particles again. In this way, an optical flash is generated each time the AC voltage is inverted. For sufficiently high frequencies of AC voltage, individual flashes are not observed by the human eye. Apart from the electrical activity of this phosphorous layer, a UV source that can be controlled separately can be used for the optical activity. Higher energy UV light activates phosphorous that emits visible light while absorbing energy. Here, the phosphorous layer is activated by two independent energy sources, power and optical power (refractive power, optical power). As a result, over a wide range, for example, even light emission is brought about by electrical activation, while the additional optical activity by UV results in more visible light locally. In this way, visible light intensity variations over the screen range can be obtained.

  The present invention will now be described by way of example only with reference to the accompanying drawings and specific embodiments.

  In FIG. 1, the basic idea of the device of the present invention is shown. This device is a planar light source 1 having a visible light source 2 and a UV source 3 schematically illustrated as a light bulb. Lights L2 and L3 are indicated generally by straight arrows and are transparent carrier screens 4 having a phosphor layer 5 that can be made and patterned from light sources 2 and 3, respectively, with glass or other transparent material. Oriented towards. The reflector 6 helps direct the backscattered radiation. Light from the visible light source passes through the phosphor layer 5 and the screen 4, while UV light is converted into visible light by the phosphor 5 before passing through the screen 4. Residual UV light is effectively suppressed by the glass screen 4. The observer 7 receives the spectrum from the visible light source combined with the converted UV light Lres, and the wavelength and spatial intensity distribution of the converted UV light is notably determined by the patterned phosphor layer 5 and the light sources L2, L3. It is governed by the radiated range.

  The phosphorous layer can be applied by a variety of techniques, such as dip coating, flow coating, screen printing, etc., to allow for an unpatterned layer structure or a patterned layer structure. Selective etching and local mechanical removal of layers is an alternative to patterning. Techniques used in the manufacture of CRT display screens can also be used.

  An alternative way of creating the pattern is to block locally the UV light from reaching the phosphor layer 5. This can be achieved by adding a glass plate formed between the light sources 3 and / or 2 and the phosphor layer 5. This formed glass plate locally prevents UV light from colliding with the phosphorous layer, resulting in a (fixed) light pattern.

  In another broad planar light source according to the first embodiment, the visible light source 2 emits blue light L2, and the phosphor 4 converts the UV light L3 into yellow radiation. In this case, the observer recognizes a light pattern resembling a blue sky with clouds.

  FIG. 2 shows an example of a flat large area light box with a visible light source 2. This light box may have a diffuser 8 to soften the light emitted by the light source. In this second embodiment, the phosphor layer 5 is mounted on top of the diffuser 8. Also, a further transparent carrier screen, not shown, can be added, with a phosphor layer applied above. The outer frame 9 carrying the observer-side window glass 10 also has a UV source directed rearward, such as an LED 3 that can be driven independently. When the LED 3 is activated, its UV light is converted into visible light by the phosphor layer 5. As a result, the observer observes the mixed visible light Lres. In the structure shown, the window glass 10 protects the viewer 7 from residual UV light. The phosphorous layer can be covered by a protective layer to enhance mechanical and chemical robustness.

  Although the examples described above focus on planar wide area light sources, the concepts of the present invention can also be applied to small lamps that are not necessarily flat. Furthermore, it must be emphasized that the first light source does not have to emit light in the visible range and can work equally well in the UV range. Phosphorus is widely used for lighting applications, for example in LEDs or in fluorescent lamps, to generate visible light or to optimize the visible office for a particular application. Displays such as CRTs used for TV and monitor applications have phosphorus to produce visible light. The individual activity of the red, green and blue phosphorous sub-pixels by the electron beam allows a light pattern to be generated in a large color gamut.

  Known fluorescent materials are YOX, BAM, BAM green, LAP, YAG, CBT, MGM, and the like. It will be apparent to those skilled in the art that many phosphorus materials or combinations can be used for the present invention.

1 is a schematic diagram of an apparatus of the present invention according to a first embodiment. FIG. 3 is a schematic diagram of an apparatus of the present invention according to a second embodiment.

Claims (13)

A surface light source,
A first light source that emits light in a first wavelength band; and a light transparent carrier screen coated with a phosphor layer;
It further comprises at least one additional light source that projects light L3 in a second wavelength band different from the first wavelength band, and the projected light L3 excites the phosphor layer. be able to,
Surface light source. The phosphor layer is arranged on one side of the carrier screen facing the object to be irradiated,
The surface light source according to claim 1. The phosphor layer is disposed on the one side of the carrier screen facing the first light source;
The surface light source according to claim 1. The carrier screen is disposed between the additional light source and the object;
The surface light source as described in any one of Claims 1 thru | or 3. The additional light source is disposed between the carrier screen and the object;
The surface light source according to claim 2. The additional light source comprises a plurality of independently controllable light sources,
The surface light source according to claim 1. At least one of the independently controllable light sources emits light in a different wavelength band than the other light sources;
The surface light source according to claim 6. The phosphorus coating has a plurality of layers and / or structures with the same or different phosphorus materials,
The surface light source according to claim 1. The first light source emits radiation in the visible wavelength range, and the additional light source emits radiation in the wavelength range and is made convertible to visible light by the phosphorous coating;
The surface light source according to claim 1. The additional light source comprises a controllable UV beamer, a scanning UV spot, or a scanning UV laser.
The surface light source according to claim 1. The material for the carrier screen has a glass, quartz, plastic, or woven structure, or a combination thereof.
The surface light source according to claim 1. The additional light source comprises a plurality of light sources having the same or different invisible wavelengths to activate different geometric ranges or to activate different phosphorous layers and exhibit different visible patterns / colors. To be
The surface light source according to any one of claims 1 to 6 and claims 8 to 11. The carrier screen for the phosphor layer has a diffuser;
The surface light source according to claim 1.

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